Ball track honing machine



Dec. 11, 1962 D. T. PEDEN ETAI.

BALL TRACK HONING MACHINE Filed Oct. 25, 1957 6 Sheets-Sheet l i4 i2 i W 1N VENTORS BY FaZew/ n/M'Znzr Dec. 11, 1962 D. T. PEDEN ETAL 3,067,547

BALL TRACK HONING MACHINE Filed Oct. 25, 1957 e Sheets-Sheet 2 INVENTORS. 7 7: 2 J a. lidziz M27255;

17 TaZIVEVSf Dec. 11, 1962 D. T. PEDEN ET A]. 3,

BALL TRACK HONING MACHINE Filed Oct. 25, 1957 e Sheets-Sheet s INVENTORST E. Jazz Z4: 73/ 21971.

Dec. 11, 1962 D. 'r. PEDEN EIAI.

BALL TRACK norms MACHINE 6 Sheets-Sheet 4 Filed Oct. 25, 1957 INVENTORS 743 7 79476 71. fiolerz *E wlq J e y BY D 1 2 0. T. PEDEN ET AL 3,067,547

BALL TRACK HONING MACHINE Filed Oct. 25, 1957 e Sheets-Sheet 5 a BY Dec. 11, 1962 D. T. PEDEN EIAI.

BALL TRACK I-IONING MACHINE 6 Sheets-Sheet 6 Filed 001;. 25, 1957 .ILU.

INVENTO fig frf 14/ M71718): ,0?

3,067,547 BALL TRACK HONING MACHINE Dougias Tillotson Peden, Ann Arbor, and Robert W. Militzer, Huntington Woods, Mich, assiguors to Micrm matic Hone Corporation, Detroit, Mich, a corporation of Michigan Filed Oct. 25, 1957, Ser. No. 692,380 7 Claims. (Cl. 5158) This invention relates to honing apparatus for surface finishing arcuate annular grooves of bearing races, and particularly for surface finishing arcuate annular grooves on the external and internal peripheray of the inner and outer race elements of a ball bearing, respectively.

Because of the vibratory nature of conventional grinding apparatus and the rapidity of wear of the grinding wheel, ball race grooves produced thereby have annular waviness and roughness and lack uniformity in their transverse cross sections.

Accordingly, the main objects of the invention are: to provide honing apparatus which improves the surface finish of a ball groove on the external and internal peripheries of the bearing races; to provide apparatus of the character indicated which will surface finish arcuate annular grooves of the inner and outer races of a ball bearing to a true circle and uniform cross section; to provide apparatus of the type mentioned which will produce such geometric accuracy and degree of surface finish of the ball groove of the inner and outer races of a bearing assembly as will permit a perfect rolling engagement with the ball mounted therein; to finish the groove of a bearing race to have a smooth uniform surface which increases the life and loadcarrying capacity of the bearing; and to provide such apparatus in a form which finishes a groove in the inner and outer faces of a plurality of ball races simultaneously without a proportionate increase in the amount or complexity of the mechanism required.

The above and related objects will become apparent when studying the following description, taken on conjunction with the accompanying drawings, wherein:

FIGURE 1 is a plan view of the honing apparatus embodying features of the present invention;

FIG. 2 is a front elevational view, with parts removed, of the structure illustrated in FIG. 1;

FIG. 3 is a side elevational view of the structure illustrated in FIG. 1;

FIG. 4 is a vertical sectional view of the structure illus trated in FIG. 2, taken along the line 4-4 thereof;

FIG. 5 is a view of structure similar to that illustrated in FIG. 2, showing another form of the invention;

FIG. 6 is an enlarged broken sectional view of the structure illustrated in FIG. 5, taken on the line 66 thereof;

FIG. 7 is an enlarged broken sectional view of the structure illustrated in FIG. 6, taken on the line 77 thereof;

FIG. 8 is a right-hand end view of the race supporting head illustrated in FIG. 6;

FIG. 9 is a view of a race supporting mechanism, showing a further form thereof;

FIG. 10 is a view of structure similar to that illustrated in FIG. 9, showing another form thereof; and

FIG. 11 is a view of structure similar to that illustrated in FIG. 10, showing a still further form of the invention.

Referring to the structure in detail, the base of the apparatus is indicated generally at 5 and mounted thereon 3,067,547 Patented Dec. 11, 1962 for vertical movement is a work spindle housing 7 rotatably carrying multiple work spindles, three of which are shown in the embodiment being described and are each indicated at 9. The work spindles 9 are arranged parallel one to another with their axes disposed in a common horizontal plane. Slideably carried in each of the spindles 9 is a work supporting fixture in the form of an arbor iii (FIG. 4) the free end of which normally projects from the forward end thereof, as shown. A vertically disposed honing tool 11 which houses a stick-type abrasive 13 is provided for each of the spindles 9. An oscillating bridge member 15 supports the tool 11 and is pivotally supported on a pair of pillow blocks 17. The abrasive sticks 13 are adapted to be advanced along axes 19 (FIG. 4) which are pivoted about the axis of pivotal movement of the bridge member 15 when the bridge member is oscillated.

The bridge member 15 is oscillatable in a circular arc the amplitude of which is indicated by the scale and pointer 16. The mechanism for actuating the bridge member 15 comprises a crank arm 21, a pitman 23 connected through a coupling 22, and a clevis 24 to a rod 25. The pitman 23 is secured to the crank 21 by a bolt 26, the head of which is slidaeable but fixedly positionable in a vertical slot 28 in the crank 21 so that the end of the pitman is movable vertically relative to the crank 21 to vary the amplitude of oscillation of the bridge member 15. The rod 25 is reciprocally driven by an eccentric cam type transmission 27 which comprises a planetary gearing system to materially reduce the rate of reciprocation of the rod 25 and hence the speed of oscillation of the abrasive sticks 13. The functioning of the planetary gearing in the transmission 27 can be conveniently controlled by timer relays (not shown) so that the oscillation of the abrasive sticks 13 is carried out preferably in two phases, a high speed oscillation phase followed by a low speed oscillation phase.

When the drive through the transmission is direct, the rod 25 is reciprocated at high speed and when the case of the transmission is released, so that the drive is through the gear system, the rod 25 is reciprocated at low speed, to thereby control the oscillation of the abrasive sticks '13 selectively at high and low speeds for roughing and finishing operations. Power is supplied to the transmission 27 through a belt and pulley arrangement, indicated generally at 29 by a motor 31 mounted on one side of the base 5. The actuation of the bridge member 15 causes each of the honing tools 11 to oscillate in unison between the positions somewhat as shown in FIG. 4 and indicated at A and B. Each honing tool 11 slidably carries in its casing or cylinder 30 a piston member 28 which engages the upper end of the abrasive stick 13 and urges it downwardly into the groove of its associated race when fluid under pressure is admitted to the top of the piston members 28 through conduits 32 at the time the spindle housing 7is elevated to its work-performing position. After the honing operation, the fluid under pressure is reversed to admit fluid below the piston members 28 so that they may be held in position or retracted when separated from the race 35. The fluid is admitted to passageways 32a and 32b in the bridge member 15 through flexible tubing (not shown) connected thereto.

Automatic work handling and feeding mechanism is disposed forward of the bridge member 15 and indicated generally at 33. The Work handling and feeding mechanism 33 includes an automatic hopper feed device and a loading cylinder 34, the piston of which actuates suitable means (not shown) capable of axially pressing a ball race 35 onto each of the arbors 10 when the spindle housing 7 is in its loading position and the arbors are advanced to their extreme forward limits, as will be later described.

The spindle housing 7 is mounted in slideways provided in a base plate 37 carried by a vertically movable ram 39 which is fluid actuated by suitable means (not shown) to collectively move the work spindles 9 between an elevated work-performing position, shown in full lines in FIG. 4, and a lowered, loading position indicated by the position of associated parts and designated by like numerals with the suflix A. When the spindle housing 7 is in its work-performing position, the pivoted axes 19 are normal to tangents to the circles of curvature of the annular grooves in the ball race 35. The travel of the ram 39 in elevating the spindle housing 7 is controlled by suitable limit'switches (not shown). While the spindle housing 7 is in itslowered position, the arbors 10 are capable of being'adv'anced axially by fluid actuating means to be described-and retained in their forward position under slight fluid pressure while the ball races 35 are pressed thereon by the work handling and feeding'mechanism 33. The amount each ball race is slid upon its respective arbor is controlled by the pressure of the fluid causing the advancement. When the ball'races 35 are pressed on the arbors 10 with the predetermined force, the arbors are retracted until the workpieces abut their respective spindle ends 36. The spindle ends 36 are accurately aligned'so that the annular grooves of the ball races lie in the same vertical plane with the pivot axis of the bridge member 15.

The forward end of each arbor 10 is tapered from its major diameter 38 to its minor diameter 46 (FIG. 4)'so as to-accommodate diameter variations in the bores of like b'all races which are to be machined. The manual adjustment of the position of the housing 7 relative to the work handling and feeding mechanism 33 is effected by the rotation of the hand wheel 41 and screw 43 supported in the base plate 37. Such adjustment is required initially for selecting the position at which the workpieces of a given type will be axially retracted when they are pressed with a predetermined force upon their respective arbors. This locates the axial position collectively of the spindle ends 36 so that the central longitudinal plane of each ball race 35 when abutting the adjacent spindle end 36 is aligned with the longitudinal plane of each of the other ball races 35 and with the pivot axis of the bridge member 15.

The construction of each spindle 9 is the same and a detailed description of the one shown in FIG. 4 will suffice for the plurality employed. The spindle 9 comprises members '45'and 47 which are joined as shown to define a piston chamber 49. The axially bored extensions of the members 45 and 47 are rotatably supported as shown in the collars -1 and 53 respectively which are fitted in oppositeends of a longitudinally extending bore 55 in the housing 7. The provision of the fluid actuating cylinder for each arbor within the spindle proper greatly simplifiesthe operating circuit. The spindle end 36 is secured to the extension of the member 45 and slideably carries the arbor10. I On the extension of the member 47 a pulley Wheel is fitted which constitutes an element of the pulley and belt assembly indicated generally at 59 by which power is supplied for rotatably driving the Work spindles 9 in common from a motor 61 mounted on the top of the housing 7.

A piston 63 is slideably disposed within the chamber 49 connected to a piston rod 65 which extends from the side 67 to the arbor 10 to which it is secured by a sleeve 69 which slides within a sleeve 71 secured to the inner end of the member 45. The sleeves 69 and 71 house a compression spring 73 located about the piston-rod 65, the spring; being freeof had until a point is reached in the &

retracting movement of the piston 63 beyond its normal retracted position at which the ball race abuts the spindle end 36. A stud 75 projects from the side 77 of the piston 63 in position to engage one end of a push rod 79 which is slideably disposed in the bore of the extension of the member 47 and urged against the stud by a compression spring 81. The other end of the push rod 79 is adapted to actuate one of the three limit switches 83 (FIG. 1) associated with the spindles 9. Each push rod 79 is operative to trip its respective limit switch at a selected distance in the retracting movement of its corresponding arbor whenever a workpiece is not properly fitted thereon. Actuation of any one of the limit switches 83 shuts off the power to the apparatus by suitable electrical connections (not shown).

Pressure fluid is admitted to and Withdrawn'from the chamber 49 through ports 85 and 87 which are formed in the longitudinally extending bore 55 and communicate with the cylinder 49 on the sides '67 and 77, respectively, of the piston 63 through apertures 80 in the member 47 and apertures 90 in the collar 53. For advancing an arbor 10, pressure fluid is admitted through the port 87 and apertures 90 to the cylinder 49 on the side 77 of the piston 63 and return fluid is withdrawn from the side 67 through the port 85 and apertures "80. The arbor is'retained in its' advanced position with a preselected force while a ball race'is being fitted thereon controlled by the pressure differential on the opposite sides of the piston 63. When'the axial force exerted on the arbor exceeds the regulated pressure dilferential on the piston 63, the loading cylinder piston of the work handling and feeding mechanism 33 retracts and simultaneously the pressure differential on the piston 63 is reversed, actuating the arbor rearwardly until the ball race pressedthereon moves against its respective spindle end 36. This is the intermediate position of the ball races in their travel between the loading and work-performing stations of the apparatus.

If, for any reason, a workpiece should fail to be retained on its respective arbor and as a result the latter is withdrawn rearwardly beyond its normal retracted position, the spring 73 will begin to be compressed between the inner end of the member 45 and the fitting 69, thus reducing considerably the rate of'inward travel of the particular arbor as it is being Withdrawn from its loosely held workpiece. When the reaction on the spring 73 approximates the force on the piston 63, the inward travel of the particular arbor is substantially stalled so that the loose workpiece thereon is'prevented from dropping off. When the movement of any one piston 63 inwardly beyond its normal rearward position corresponding to the normal intermediate position of the workpieces, because its corresponding arbor received no workpiece or because one has become accidentally dislodged, is sensed by the push rod '79, the push rod trips its corresponding limit switch 83 to render the apparatus inoperative, thereby preventing damage to the corresponding arbor and its abrasive stick.

The planetary gear transmission 27 will oscillate the bridge member 15 by a direct drive connection through the holding of the case-by a spring advanced plunger of the transmission. A solenoid is energized to retract the plunger near the end of the honing operation to-permit the case to rotate and to drive through the planetary gearing. This produces a low speed drive for the bridge member 15 near the end of the honing operation to produce a high polish to the surface of the honed track. Upon the timing out of a timer relay controlling the duration of the high speed oscillation phase, a second timer relay times the low speed oscillation phase after the solenoid 95 is energized to retract the plunger to permit the planetary case to rotate. When the low speed timer relay times out, the work-performing operation on the ball race 35 is completed.

The details of the electrical circuit for controlling the cycles of operation of the apparatus are not shown as it does not constitute a part of the present invention, it

being deemed sufiicient to state that energization of the electrical circuit is accomplished by actuation of buttons 89 on a control station 91 mounted on the base 5. The cycle of operation of the apparatus is commenced when the spindle housing 7 is in its lowered position by admitting pressure fluid to each of the chambers 49 to effect a pressure unbalance on the pistons 63 therein to advance the arbors 10 axially forward to their extreme limit adjacent the work handling and feeding mechanism 33. The hopper feed portion of the latter advances a plurality of workpieces 35 toward the means actuated by the piston of the loading cylinder 34 which presses them on the arbors 10. When the axial force on each of the arbors 10 exceeds the predetermined force on the corresponding piston 63 at the differential pressure then existing in each of the chambers 49, the piston of the loading cylinder retracts and simultaneously the pressures unbalance on the pistons 63 in each of the chambers 49 is reversed to retract the arbors 10 inwardly until the ball races 35 thereon abut against their respective spindle ends 36.

The ram 39 (FIG. 2) is then elevated until the workperforming position of the housing 7 is reached, wherein the center of curvature of each of the engaging ends of the abrasive sticks 13 coincides with the center of curvature of the annular track groove in each of the ball races 35. Thereupon, the motors 31 and 61 are energized, driving the spindles 9 in rotation and the bridging member 15 is oscillation. Concurrently with the energization of the motors 31 and 61, pressure fluid is admitted to the fluid conduits 32 of each of the honing tools 11 to force the piston 28. therein, downwardly pressing the abrasive sticks 13 against the track surface of the ball races 35. The races 35 are rotated at a relatively high constant speed, while the abrasive sticks 13 are oscillated about the center of curvature of the engaged ends also at a relatively rapid rate until a sufficient amount of metal has been removed from the ball races to produce the correction desired in the contour and smoothness of their track surfaces. Thereafter, the planetary gearing in the transmission 27 is actuated to materially reduce the rate of oscillation of the bridging member 15 and hence of the abrasive sticks 13 while the yieldable pressure is maintained between them and the rotating ball races 35. During the low speed oscillation phase of the abrasive sticks, a reduction in their breakdown rate and consequently a slight glazing thereof occurs. The quality of surface finish during this glazing or sparking out of the abrasive sticks is refined beyond that which they normally produce at their high speed oscillation phase.

' After the timer relay corresponding to the low speed oscillation phase of the abrasive sticks has completed its cycle, a reversal of the actuation of the various solenoid valves is effected to reverse the sequence of operation of the apparatus. The ram 39 is then actuated downwardly, withdrawing the workpieces from contact with the abrasive sticks and cutting off the flow of pressure fluid to the fluid conduit 32 of each of the honing tools 11. When the spindle housing 7 reaches its lowered position, the pressure in each of the chambers 49 at the side 67 of the piston 63 therein is rapidly increased, causing retraction of the arbors 10 and their withdrawal from the finished ball races, dropping the latter into suitable discharge chutes (not shown) which transport them from the machine. The various parts of the machine are then in position for repetition of the cycle of operations described above which occur automatically but which may be manually sequenced if desired.

Referring to FIGS. 5 and 6 another form of the machine illustrated in FIGS. 1 to 4 is shown, employed for honing the outer race of a ball hearing. The machine is the same as that hereinabove described with the exception that the oscillating bridge member 93 supports a plurality of stone feeding mechanisms 94 from the bottom rather than the top of the bridge. This permits the stone to enter the race and to engage the inner track thereofand to be retained with a predetermined pressure against the track surface as the stone is oscillated on the center of curvature of the track. A different work supporting element is employed in the machine of FIGS. 5 to 8. This comprises a supporting cylinder 97 having a piston 98 connected to a rod 99. The rod reciprocates a clamping element 101 within a sleeve 102 which is secured to the forward end of the cylinder 97. A cylinder 103 is supported within the sleeve 102 to which the rod 99 is sealed by an O-ring 104. A cylinder 105 is mounted within the sleeve 102 in continuation of the sleeve 103 carrying on its forward end a work supporting head 106. A nut 107 engages a split ring 108 when engaging the threaded end of the head 106 to secure it in extension of the end of the sleeve 102. A pin 109 prevents the relative rotation between the sleeve and the head. The head 106 has a hollow interior 111 in which a clamping head 112 on the end of the clamping element 101 is mounted. A seal 113 about the reciprocating member 101 provides a seal for the element against the inner wall of the cylinder 105. The element 101 is secured by a screw 114 to the end of the rod 99 to reciprocate therewith. The forward end of the central aperture 115 is sealed by a plug 116.

A work supporting fixture in the form of a clamping head 117 is secured by a plurality of screws 120 to the forward face of the head 106 so that different size workpieces may be machined through the expediency of changing the head 117 to one having a workpiece receiving aperture of greater or less diameter. The head 106 has a slot 118 into which a workpiece 96 may be dropped to be aligned with the clamping head 117. The head 112 is then advanced by the rod 99 to push the workpiece 96 against a forward shoulder 121 to clamp it thereagainst in position to be rotated when the cylinder 97 is rotated. As is evident from FIGS. 6, 7 and 8, the head 112 has three fingers 122 secured thereto preferably by welding, brazing or the like, in position to have a projecting end abut the workpiece 96 when aligned with the flange 121, as clearly illustrated in FIG. 6. After the track has been honed, the retraction of the rod 99 causes the fingers 122 to move the workpiece 96 into alignment with the slot 118, permitting the workpiece to drop therefrom when the cylinder 97 has been stopped in position to have the slot 118 presenting downwardly. After the workpieces have dropped from the head, the cylinder 97 is rotated 180 to have the slot 118 positioned at the top, as illustrated in FIGS. 6, 7 and 8. Additional slots 123 may be provided in the part of the head opposite the slot 118 to permit the coolant which is delivered to the track during the honing operation to flow out of different parts of the periphery of the head, to thereby keep the three fingers 122 free of grit and abraded particles when in position to receive the next race to be honed.

The oscillatable bridge member 93 supports a plurality of the stone holding and advancing devices 125, each having a forwardly projecting portion 127 containing a slot 128 in which an abrading stone 129 is mounted for downward movement. The stone has a cap 131 on the upper end which is guided in a widened portion 132 of the slot which strengthens the upper part of the stone engaged by the operating lever 133. Rubber means such as an O-ring 134 is supported in slots 135 at the sides of the forwardly projecting portion 127, as illustrated in FIG. 7, to extend therethrough at the ends for engaging the forward and rearward edges of the stone and retaining it in adjusted position with a desired amount of friction, as illustrated in FIGS. 4 and 6. The lever 133 is mounted on a pivot 136; the end 137 opposite to that which engages the cap 131 is engaged by the end of a rod 138. The rod is moved upwardly by a piston 139 within a cylinder 141 when fluid is delivered to the lower end thereof from a conduit 142 and is retracted by fluid from a conduit 143. The fluid is delivered to the one or plurality of cylinders 141 from passageways 144 and 145 which extend through the bar 94 and to and from which the fluid is conducted.

The race 96 is dropped into the slot 118 of the head and the piston 98 is advanced to move the rod 99 and clamping element 101 to secure the race 96 in forward position within the head 117. Thereafter, the cylinders 97 are advanced forwardly to have the tracks of the races 96 aligned with the stones 129 whereupon the cylinders 97 are moved upwardly to move the tracks into engagement with the ends of the stones. Thereafter the bar 93 is oscillated as pressure is applied to the end of the stone by the lever 133 which produces an abrasive action to the track of the race as the stone oscillates on the center of the arc of the track. After the honing operation, the oscillation of the bar 93 is interrupted, the delivery of fluid to the cylinder 141 is reversed, the cylinders 97 are moved downwardly and then retracted rearwardly to be separated from the forward end 127 of the stone holding and advancing devices 125 after which the piston 98 is retracted, retracting the head 112 of the clamping element 101, the fingers 122 of which move the race into alignment with the slot 118 which faces downwardly so as to permit the race to drop therefrom. The cylinder 97 is stopped with the slot 113 facing downwardly, and after the race drops therefrom is rotated 180 to locate the slot 118 at the top in position to receive the next race to be honed. I Accordingly, by changing the clamping means and the tools, the machine may be employed for honing the track of the inner and outer race of a ball bearing.

In FIGS. 9, and 11 a further type of clamping means is illustrated which may advantageously be employed for securing the inner race clamped upon a spindle 156 of a rotatable arbor 151. After the arbor is advanced forwardly to be aligned with the honing stone 13 and is raised to have the track move into engagement therewith, the outer race 152 of a ball bearing 153 is engaged thereby, the ball bearing is mounted upon a spring-pressed stud 154 on an arm 155 which is laterally adjustable on a support 156. The corner of the race 152 engages the forward face of the race 149 to force it rearwardly against the shoulder of the arbor 151 and downwardly to maintain a line engagement with the spindle 1S5) directly on the line of engagement of the stone 13 with the track. In other words, the line of honing occurring to the track 157 of the race 149 is exactly aligned with the line of engagement of the race with the spindle 150.

This same relationship obtains in the structure of FIG. 10 wherein an arbor 153 is mounted within a supporting sleeve 159 having an extending truncated conical head 161 mounted for rotation against a thrust bearing 162. The sloping surface of the head 161 engages a corner of the race 149 to force it against the shoulder of the arbor 151 as it is held in engagement with the spindle th in a line directly opposite to the line on which-honing is produced by the stone 13 in the track 157 of the race.

A further form of the invention is illustrated in FIG. 11 wherein the end of an arbor 163 contains a ball 164' which engages-the race 149 when the arbor 151 is moved upwardly. The race is forced against the shoulder of the arbor and against the spindle 150 by the ball to provide a line engagement opposite to the line upon which the honing operation occurs. Such support ing devices may be substituted for the tapered spindles 10 which have been hereinabove described with regard to the structure of FIGS. 1 to 4 inclusive.

What is claimed is:

1. In a machine for honing a ball track in a peripheral face of a ball race, a plurality of abrasive stones having an arcuate end, means for supporting said stones for oscillation in a common plane on the centers about which said arcuate ends were struck, means applying a pressure to the ends of the stones opposite to that having the arcuate end, a plurality of rotatable elements having their axes in spaced relation, 2. fixture on each element for supporting a ball'race with the ball tracks thereof in aligned relation with each other, means for advancing said' elements toward the stones for aligning the tracks therewith, means for raising said elements and races into engagement with an associated stone, means for rotating said elements and races, means for operating said oscillating means, and means for lowering and retracting said elements and releasing the finished races.

2. A machine for honing a ball track in a peripheral face of a ball race including a base, a spindle rotatably supported on said base, means for driving said spindlein rotation, a work supporting fixture at one end of saidspindle engageable with one of the peripheral surfaces of a ball race for supporting the ball race for rotation by said spindle, said work supporting fixture being arranged to receive ball races from one end thereof, an oscillating bridge member, means supporting said bridge member for oscillation about an axis perpendicular to the axis of said spindle, a honing tool carried by said bridge member, said honing tool having an abrasive element provided with an arcuate end adapted to engage a ball race to be honed, means for biasing said abrasiveelement in a direction toward the arcuate end-thereof, means for relatively moving the axis of oscillationgof said bridgememher and said base member in a direction perpendicularto both the axis ofoscillation of said bridge member and the axisgof-rotationof said spindle, and means for feeding ball races into engagement withsaid work supporting fixture at said one end thereof; n N g g V 3. The structure set forth in claim; 2 Which said honing tool includesa fluid pressure cylinder secured to said bridge member. V H i v i i 4. The structure set forth in claim 3' in which said bridge member is formed with passages in communication with the interior of said cylinder for supplying fluid under pressure to said cylinder. i

5. A honing tool adapted to be used in a ball'race honing machine having means for rotatably supporting a ball race to be honed and an oscillating member for supporting the honing tool, said honing tool including a cylinder, a piston movable longitudinally in'said cylinder, an elongated abrasive stone extending longitudinally within said cylinder in spaced relation thereto and projecting from said cylinder at one end thereof for engagement with a ball race to be honed, means on one side of said piston receiving the end of said abrasive element opposite from the end thereof projecting from said cylinder, and means for app-lying fluid pressure to the side of said piston opposite from the side at which said abrasive stone is received, said-piston being movable upon the wearing of said abrasive stone through a portion of said cylinder which is occupied by said stone when said stone is substantially unused.

6. The structure set forth in claim 5 in which said cylinder is provided with means at said one end thereof for supporting and engagingsaid abrasive stone as it is advanced therethrough.

7. A machine for honing ball tracks in the peripheral faces of ball races including a base, a plurality of rotary spindles'supported on said base with the axes of rotation thereof disposed in parallel co-planar relation, a work supporting fixture at one end of each of said spindles for supporting a ball race for rotation by said spindle, said fixtures being arranged to receive ball races from one end thereof, an oscillating bridge member, means supporting said bridge member for oscillation about an axis perpendicular to the axes of said spindles, a plurality of honing tools carried by said bridge, each of said honing tools having an abrasive element provided with an'arcuate end adapted to be positioned in operative relation to a ball track supported on one of said work supporting fixtures, means for biasing each of said abrasive elements in a direction toward the arcuate end thereof, means for relatively moving'the axis of oscillation of said bridge member and said base in a direction perpendicular to said axis of oscillation of said bridge member References Cited in the file of this patent UNITED STATES PATENTS Kasson Jan. 13, 1903 Beck Sept. 27, 1921 10 Moon Oct. 31, 1939 Pew Aug. 12, 1941 Indge Oct. '7, 1941 Deuring Feb. 1, 1944 Marren Apr. 9, 1946 Jackson Aug. 27, 1946 Miller Oct. 21, 1952 Taylor Sept. 7, 1954 Schorling et a1. May 7, 1957 

